Spain has launched legal action against US marine explorers over a wreck they have found laden with treasure.

The wreck has been described, speculatively, as a 17th Century vessel, found off the coast of England, containing $500m (£253m) in coins.

However, there have also been rumours that it was found off Spain. Odyssey Marine Exploration would only say it was found in the Atlantic Ocean.

A lawyer said if the vessel was Spanish any treasure would belong to Spain.

Jim Goold, of the law firm Covington & Burling, representing the Spanish government, told the BBC: "The lawsuit will challenge Odyssey Marine Explorers' right to recover or possess any property of the Kingdom of Spain recovered from sunken ships.

"Odyssey has been requested to provide information concerning the identity of the ship and the material recovered, and has failed to respond."

Odyssey has been requested to provide information concerning the identity of the ship and the material recovered

Lawyer Jim Goold

Odyssey would not make any further comment when contacted by BBC News.

It has so far sent 17 tons of coins recovered from the wreck back to the US for examination. It says the discovery is the biggest of its kind.

Mr Goold has represented the Kingdom of Spain over shipwreck cases before, involving the recovery of material from two ships, Juno and La Galga, in a 2000 court case. The Spanish government won the case.

Mr Goold said the Spanish government had never abandoned its sunken ships. "Salvage operations without Spanish permission are not acceptable," he said.

'Contraband dealing'

Spanish media have reported that Odyssey Marine Exploration vessels had been seen with flags denoting they were undertaking marine research in Spanish waters in recent months.